<html>
<body>
<h1>JavaScript Dates</h1>
<p>Add zeros and colons to display the time:</p>
<p id="demo"></p>
<script>
function addZero(x,n) {
while (x.toString().length < n) {
x = "0" + x;
}
return x;
}
const d = new Date();
let h = addZero(d.getHours(), 2);
let m = addZero(d.getMinutes(), 2);
let s = addZero(d.getSeconds(), 2);
let ms = addZero(d.getMilliseconds(), 3);
let time = h + ":" + m + ":" + s + ":" + ms;
document.getElementById("demo").innerHTML = time;
</script>
</body>
</html>